OpenAI said today it is making GPT-5.6 Luna the default model for Free and Go ChatGPT users, replacing GPT-5.5 Instant and giving those users access to a newer, more capable model. Free and Go users will be able to access unlimited text chats with no text-based rate limits; limits will still apply for file uploads, images and other ChatGPT tools. A new Think button that turns on higher reasoning is also coming.
GPT-5.6 Sol for Plus and Pro
For Plus and Pro users, OpenAI said GPT-5.6 Sol is more reliable with facts and delivers more focused answers. The company added a slider to let users select how much thought ChatGPT puts into a response, and it tweaked how much detail the model offers to prevent giving extra information when it is not needed. OpenAI says GPT-5.6 Sol will avoid unnecessary formatting and will offer a “helpful correction when simply agreeing wouldn’t be useful.” The update is intended to produce fewer mistakes, particularly when answers depend on dates, numbers, sources, rules or assumptions. The Sol update applies only to Chat; the version for Work and Codex remains unchanged.
GPT-5.6 Luna for Free and Go
OpenAI said ChatGPT’s Instant and Thinking experiences now have a more consistent tone and behavior so it does not feel like switching to a model with a different tone or style. Plus and Pro users have access to the updated GPT-5.6 Sol and the thought slider starting today. GPT-5.6 Luna is becoming the default model for Free and Go users this week, with unlimited text chats and the Think button arriving next week.
These changes apply to the ChatGPT app for iPhone, iPad and Mac.
